Danville gets a 5 digit zip code (1963)

source: The Republican (Danville, Indiana) - issue of Thursday, June 27, 1963 - page 1, columns 4-5:

According to a newspaper article, effective July 1, 1963 Danville would get a 5-digit zip code, 46122, which was to be used in addressing mail. This was part of a new nationwide postal delivery system designed to speed up delivery. The first digit of a 5-digit zip code identified the geographical area, the second and third digits identified the major city or sectional center, and the fourth and fifth digits identified the delivery unit.